• Title/Summary/Keyword: pH 측정 시험

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Relationship between Eradication of Helicobacter pylori Infection and Clarithromycin Resistance (Helicobacter pylori 감염의 치료와 Clarithromycin 내성간의 연관성)

  • Sohn Seung Ghyu;Lee Jong Hwa;Lee Jung Hun;Lee Sang Hee
    • Korean Journal of Microbiology
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    • v.41 no.3
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    • pp.177-182
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    • 2005
  • H. pylori strains were isolated from antral biopsies taken during upper endoscopy in 114 dyspeptic patients with no previous therapy against H. pylori. Rapid urease test, PCR amplification of SSA and cagA gene for H. pylori detection, and Western blot for CagA expression detection were performed. H. pylori infected patients were treated with omeprazole, clarithromycin (a macrolide), and amoxicillin. At 6 weeks after the discontinuation of therapy, the bacterial eradication rate was determined by endoscopy. The resistance rate to clarithromycin and amoxicillin was $20.2\%$ and $0.0\%$, respectively. The clarithromycin resistance was mainly caused by the A2142G mutation in the 23S rRNA gene of H. pylori. MICs of clarithromycin for the A2142G mutant isolates were significantly higher than MICs for the A2143G mutant isolates. H. pylori eradication was obtained in all patients with clarithromycin-susceptible isolates but not in patients with clarithromycin-resistant isolates (P = 0.0001). These results did not appear to be biased by any differences in CagA expression. The resistance of H. pylori to clarithromycin included in the therapeutic regimens is the most important reason for treatment failure. H. pylori antimicrobial susceptibility testing of the gastric biopsy culture should be performed before choosing the first triple therapy in infected patients and the increase in prevalence of clarithromycin resistance in Korea was problematic.

Application and High Throughput Screening of DPPH Free Radical Scavenging Activity by Using 96-Well Plate (96-well plate를 이용한 DPPH free radical 소거활성 측정과 그 응용)

  • Choi, Jung-Sup;Oh, Jung-Im;Hwang, In-Taek;Kim, Sung-Eun;Chun, Jae-Chul;Lee, Byung-Hoi;Kim, Jin-Seok;Kim, Tae-Joon;Cho, Kwang-Yun
    • The Korean Journal of Pesticide Science
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    • v.7 no.2
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    • pp.92-99
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    • 2003
  • A 96-well plate was applied to determine the DPPH free radical scavenging activity using 107 plant-specific enzyme inhibitors and 100 unknown plant-originated extracts. The final optimum volume was $250{\mu}L$ containing $100{\mu}M$ DPPH ethanolic solution at pH 7.8. In this condition, the radical scavenging activities were significantly increased by two known antioxidants consisting of ascorbate and a-tocopherol in a concentration-dependent manner. Among the 107 inhibitors, ampicillin and gallic acid showed 90.2% and 92.6% antioxidant activity at $100{\mu}M$, respectively, and these results were consisted with previous findings. In the tested 100 natural materials at $50{\mu}g/mL$, antioxidant activity of AT-407 resulted in the highest of 90.1%, and 10 extracts including AT-388 and AT-443 showed over 70%. Our results suggest that the use of 96-well plate for determining DPPH free radical scavenging activity would be a suitable method to select antioxidant-like substances of both synthetic compounds and natural products.

Effects of Vital Wheat Gluten on Quality Characteristics of White Pan Bread Containing Resistant Starch (활성글루텐이 저항전분을 함유한 식빵의 품질 특성에 미치는 영향)

  • Kim, Yu-Jin;Lee, Jeong-Hoon;Choi, Mi-Jung;Choi, Doo-Ri;Lee, Si-Kyung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.1
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    • pp.76-82
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    • 2013
  • This study was carried out to evaluate the effect of wheat gluten on quality characteristics of white pan bread with 10% resistant starch. White pan bread was fortified with wheat gluten at levels of 2%, 4% and 6% w/w. The pH of dough and white pan bread, specific loaf volume, water activity, baking loss rate, crumb color, hardness, and sensory evaluation were analyzed for quality characteristics. The pH of processed dough and white pan bread with additional vital wheat gluten was lower than that of control, and pH increased with increasing wheat gluten content. Water activity was lower in white pan bread with added vital wheat gluten than in the control, however there were no significant differences. Specific loaf volume revealed a higher value in tests than in the control, and the products revealed a higher specific loaf volume with higher amounts of vital wheat gluten. However, the baking loss rate decreased with increasing wheat gluten content. In terms of crumb color analysis, L, a, and b values lowered with increasing wheat gluten. Hardness appeared to be lower in tests than in the control, and the test with 6% wheat gluten showed the lowest value among the products. In a sensory evaluation, the product with 4% wheat gluten revealed the highest score. As a result of this study, 4% wheat gluten is considered to be the reasonable level in preparing white pan bread with 10% resistant starch.

Studies on the physical properties of soybean curd stored in the solution of different salt concentration (침지저장액에 따른 두부의 물성 변화에 관한 연구)

  • Jang, Won-Young;Shin, Dong-Hoon;Kim, Byung-Yong
    • Applied Biological Chemistry
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    • v.38 no.2
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    • pp.135-140
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    • 1995
  • Changes in pH of the soaking solution and physical properties of the soybean curd during immersing in solution of different concentrations at different temperatures were determined. Compared with $0{\sim}3%$ NaCl soaking solution, 5% NaCl soaking solution distinctively reduced the pH drop, increasing rate of turbidity and microorganism growth during storage. This indicated the concentration of soaking solution influences the shelf life of curd. As the storage temperature was lowered to $5^{\circ}C$, their changing rates were also reduced. Physical properties such as initial stress $({\sigma}_0)$, elastic constant (E), viscous constant $({\eta})$ and failure test were influenced by storage temperature, but not a function of concentration of salt solution. The result of the sensory test indicated the hardness and salty taste of curd were statistically significant among samples and $1{\sim}5%$ NaCl solutions did not show any significant difference in the salty taste.

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Physiological Characteristics and Tyrosinase Inhibitory Activity of Lactobacillus plantarum M23 Isolated from Raw Milk (원유에서 분리한 Lactobacillus plantarum M23의 Tyrosinase 활성 저해 및 생리적 특성조사)

  • Heo, In-Sook;Kim, Kee-Sung;Yang, Seung-Yong;Lee, Nam-Hyouck;Lim, Sang-Dong
    • Food Science of Animal Resources
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    • v.27 no.4
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    • pp.501-508
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    • 2007
  • In order to develop a new starter for fermented milk, Lactobacillus plantarum M23 was isolated from raw milk and investigated for physiological characteristics. It showed good tyrosinase inhibitory activity compared with commercial lactic acid bacteria. The optimum growth temperature of Lactobacillus plantarum M23 was $40^{\circ}C$ and cultures took 17 hr to reach pH 4.3. Lactobacillus plantarum M23 showed more sensitivity to Penicillin-G, Oxacillin, Novobiocin, Chloramphenicol in a comparison of 12 different antibiotics, and showed most resistance to Vancomycin. It showed higher leucine arylamidase and ${\beta}-galactosidase$ activities compared to 16 other enzymes. It was comparatively tolerant to bile juice and able to survive at pH 2 for 3 hours. It showed high resistance to Escherichia coli, Salmonella typhimurium and Staphylococcus aureus with rates of 77.8%, 86.5% and 83.8%, respectively. Based on these and previous results, Lactobacillus plantarum M23 could be an excellent starter culture for fermented milk with high resistance to melanin.

Shampoo Characteristics of Botanical Extract Containing Green Tea, Saururus chinensis and Prunus padus (녹차, 삼백초, 귀룽나무 등을 포함한 식물성 추출물의 샴푸로서의 특성)

  • Hwang, Danbi;Shin, Hyejin;Jeong, Hyangli;Noh, Daeyoung;Kim, Misung;Kim, Jinhong;Kim, Donguk
    • Korean Chemical Engineering Research
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    • v.53 no.6
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    • pp.663-666
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    • 2015
  • In this research, botanical extracts containing green tea, Saururus chinensis and Prunus padus were tested to see possibility as shampoo. Leaves of Green tea and Saururus chinensis were extracted with hot water. Prunus padus bark extract was applied reverse osmosis and ultrasonic extraction. When interfacial tension was measured among shampoo including botanical extracts, Sodium dodecylsulfate(SDS) and Quillaja Bark Saponin(QBS), that of shampoo was lower than that of SDS and QBS at lower concentration, however, it showed similar interfacial tension at 100% concentration. Shampoo showed moderate antimicrobial activity in Staphylococcus aureus and Candida albicans. Botanical extract did not indicate cell toxicity up to $350{\mu}g/ml$ concentration in MTT assay. Shampoo containing botanical extract was stable for 3 months, however, it showed considerable variation in pH and viscosity. In conclusion, shampoo containing botanical extract shows strong possibility for natural shampoo if the formulation is modified.

Effect of Packaging Material and Storage Temperature on the Quality of Tomato and Plum Fruits (포장재 및 저장온도가 토마토와 자두의 품질에 미치는 영향)

  • 이세희;이명숙;이용우;염형준;선남규;송경빈
    • Food Science and Preservation
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    • v.11 no.2
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    • pp.135-141
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    • 2004
  • To examine the quality changes of tomato and plum fruits during storage under various storage conditions, the rate of weight loss, pH change, titratable acidity, Hunter a value, firmness, and anthocyanin content were determined during storage. Tomato and plum fruits were stored at 4$^{\circ}C$ and 25$^{\circ}C$. Tomato fruits were packaged with high density polyethylene film (HDPE) and polyvinylidene chloride film (PVDC), and plum fruits were packaged with HDPE. Tomato fruits packaged with PVDC and plum fruits packaged with HDPE at 4$^{\circ}C$ were the most desirable in terms of weight loss. Titratable acidity of tomato fruits decreased with increasing storage time regardless of temperature and packaging method. Hunter a value of tomato fruits stored at 25$^{\circ}C$ increased regardless of packaging method, while it was not changed for tomato fruits stored at 4$^{\circ}C$. Firmness of plum fruits stored at 25$^{\circ}C$ significantly decreased during storage and anthocyanin content increased. Microbial numbers of tomato fruits increased during storage, but its rate was retarded during storage when tomato fruits were packaged with HDPE and stored at 4$^{\circ}C$. These results suggest that cold chain system and appropriate packaging could maintain the quality and prolong the shelf life of fresh produce.

Antimicrobial Activity of Korean Leek and Its Application to Food System (부추의 항균활성 특성과 식품에의 응용)

  • 홍정화;이미형;전치수;허성호
    • Journal of Food Hygiene and Safety
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    • v.14 no.4
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    • pp.422-427
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    • 1999
  • Antimicrobial activity of Korean leek was effective on Staphylococcus aureus, Bacillus cereus, Bacillus subtilis, E. coli O157:H7, Pseudomonas fluorescens, Pichia membranaefaciens. Extract from raw Korean leek and that from frozen one showed antimicrobial activity; in contrast, extract stored frozen condition or extract from blanched one lost antimicrobial activity. Filtration, centrifugation, and vacuum concentration did not affect antimicrobial activity of the leek, nor did the changes in storage pHs. Addition of ground leek to soy milk, soy curd, and broth for cold noodle resulted in the prolonged shelf life by significantly reducing the number of viable cells.

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Radiolabeling of NOTA and DOTA with Positron Emitting $^{68}$Ga and Investigation of In Vitro Properties (양전자 방출핵종 $^{68}$Ga을 이용한 NOTA와 DOTA의 표지 및 시험관내 특성 연구)

  • Jeong, Jae-Min;Kim, Young-Ju;Lee, Yun-Sang;Lee, Dong-Soo;Chung, June-Key;Lee, Myung-Chul
    • Nuclear Medicine and Molecular Imaging
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    • v.43 no.4
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    • pp.330-336
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    • 2009
  • Purpose: We established radiolabeling conditions of NOTA and DOTA with a generator-produced PET radionuclide $^{68}$Ga and studied in vitro characteristics such as stability, serum protein binding, octanol/water distribution, and interference with other metal ions. Materials and Methods: Various concentrations of NOTA 3HCl and DOTA 4HCl were labeled with 1 mL $^{68}$GaCl$_3$ (0.18$\sim$5.75 mCi in 0.1 M HCl in various pH. NOTA 3HCl (0.373 mM) was labeled with $^{68}$GaCl$_3$(0.183$\sim$0.232 mCi/0.1 M HCl 1.0 mL) in the presence of CuCl$_2$, FeCl$_2$, InCl$_3$, FeCl$_3$, GaCl$_3$, MgCl$_2$ or CaCl$_2$ (0$\sim$6.07 mM) at room temperature. The labeling efficiencies of $^{68}$Ga-NOTA and $^{68}$Ga-DOTA were checked by ITLC-SG using acetone or saline as mobile phase. Stabilities, protein bindings, and octanol distribution coefficients of the labeled compounds also were investigated. Results: $^{68}$Ga-NOTA and $^{68}$Ga-DOTA were labeled optimally at pH 6.5 and pH 3.5, respectively, and the chelates were stable for 4 hr either in the reaction mixture at room temperature or in the human serum at 37$^{\circ}C$. NOTA was labeled at room temperature while DOTA required heating for labeling. $^{68}$Ga-NOTA labeling efficiency was reduced by CuCl$_2$, FeCl$_2$, InCl$_2$, FeCl$_3$ or CaCl$_3$, however, was not influenced by MgCl$_2$ or CaCl$_2$. The protein binding was low (2.04$\sim$3.32%). Log P value of $^{68}$Ga-NOTA was -3.07 indicating high hydrophilicity. Conclusion: We found that NOTA is a better bifunctional chelating agent than DOTA for $^{68}$Ga labeling. Although, $^{68}$Ga-NOTA labeling is interfered by various metal ions, it shows high stability and low serum protein binding.

Basic Study on the Development of Analytical Instrument for Liquid Pig Manure Component Using Near Infra-Red Spectroscopy (근적외선 분광법을 이용한 돈분뇨 액비 성분분석기 개발을 위한 기초 연구)

  • Choi, D.Y.;Kwag, J.H.;Park, C.H.;Jeong, K.H.;Kim, J.H.;Song, J.I.;Yoo, Y.H.;Chung, M.S.;Yang, C.B.
    • Journal of Animal Environmental Science
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    • v.13 no.2
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    • pp.113-120
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    • 2007
  • This study was conducted to measure Nitrogen(N), Phosphate($P_2O_5$), Potassium ($K_2O$), Organic matter(OM) and Moisture content of liquid pig manure by Near Infrared Spectroscopy(NIRS) and to develop an alternative and analytical instrument which are used for measurement of N, $P_2O_5$, $K_2O$, OM, and Moisture contents for liquid pig manure. The liquid pig manure sample's transmittance spectra were measured with a NIRS in the wavelength range of 400 to 2,500 nm. Multiple linear regression and partial least square regression were used for calibrations. The correlation coefficient(RSQ) and standard error of calibration(SEC) obtained for nitrogen were 0.9190 and 2.1649, respectively. The RSQ for phosphate, potassium, organic matter and moisture contents were 0.9749, 0.5046, 0.9883 and 0.9777, and the SEC were 0.5019, 1.9252, 0.1180 and 0.0789, respectively. These results are indications of the rapid determination of components of liquid pig manure through the NIR analysis. The simple analytical instrument for liquid pig manure consisted of a tungsten halogen lamp for light source, a sample holder, a quartz cell, a SM 301 spectrometer for spectrum analyzer, a power supply, an electronics, a computer and a software. Results showed that the simple analytical instrument that was developed can approximately predict the phosphate, organic matter and moisture content of the liquid pig manure when compared to the analysis taken by NIRS. The low predictability value of potassium however, needs further investigation. Generally, the experiment proved that the simple analytical instrument was reliable, feasible and practical for analyzing liquid pig manure.

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